<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>循环添加事件</title>
</head>

<body>
  <button index='1'>按钮1</button>
  <button index='2'>按钮2</button>
  <button index='3'>按钮3</button>
  <script src="./06-add-event-loop.js"></script>
</body>

</html>